Pedestrian Hazard, Awareness, and Safety Expansion Act of 2023 or the PHASE Act of 2023 This bill directs the National Institute of Standards and Technology (NIST) and the Department of Transportation (DOT) to take certain actions to improve road safety for pedestrians and vulnerable road users. Specifically, the bill directs NIST to transmit to DOT potential solutions to improve and enhance traffic control devices using innovative technologies in order to better equip vehicle operators (including bicycles) and protect pedestrians and vulnerable road users. In addition, DOT must establish a grant program to provide grants to cities, Indian tribes, and municipalities to implement infrastructure that improves pedestrian safety (e.g., innovative technology for crosswalks, expanded buffer zones, and upgraded highway traffic signals). DOT must also carry out a study on developing physical alternatives to better protect pedestrians and vulnerable road users from traffic incidents.